1. Field
The disclosed and claimed concept relates generally to circuit interrupters and, more particularly, to an improved indicator apparatus to indicate an OPEN or CLOSED condition of a circuit interrupter.
2. Related Art
Circuit interrupters of various types are well known in the relevant art and are generally used to open a protected portion of a circuit during certain predefined conditions such as certain overcurrent conditions, under-voltage conditions, fault conditions, and the like. Circuit interrupters thus typically have a CLOSED condition wherein the protected portion of the circuit is closed and an OPEN condition in which the protected portion of the circuit is OPEN. The OPEN condition of the circuit interrupter can include both an OFF condition and a TRIPPED condition of the circuit interrupter, by way of example. A typical circuit interrupter may include a set of separable contacts which, when separated, open the protected portion of the circuit. Such circuit interrupters typically also include a mechanism of any of a variety of types that are well known in the relevant art that control movement of the set of separable contacts between the OPEN and CLOSED conditions of the circuit interrupter.
Certain types of circuit interrupters can include an indicator that may indicate either or both of the OPEN and CLOSED conditions of the circuit interrupter. Such an indicator may include one or more flags upon which words such as “OPEN”, “CLOSED”, and the like may be displayed at various times depending upon the condition of the circuit interrupter, and/or the flags may include, by way of example, green or red coloring to indicate the condition of the circuit interrupter. Such indicators typically have been connected in one fashion or another with the mechanism that controls the separation of the set of separable contacts. While known circuit interrupters have been generally effective for their intended purposes, they have not been without limitation.
Indicators of this type have occasionally become broken during a trip event due to an inability to withstand the kinetic energy that is applied to such indicators during the trip event, i.e., wherein the set of separable contacts of the circuit interrupter can be caused to separate extremely rapidly. Also, some indicators have experienced difficulty in accurately indicating the OPEN and CLOSED conditions when switching states of the circuit interrupter due to a mechanical delay that results from a relatively large movement in changing states of the set of separable contacts compared with a relatively small movement in changing states of an indicator. That is, a set of separable contacts may be electrically isolated from one another (thus causing the portion of the circuit that is protected by the circuit interrupter to be in an open condition) when the set of separable contacts are separated from one another by as little as one-quarter of an inch, but the mechanism that separates the set of separable contacts may continue to move the contacts apart until they are, say, an inch apart. If the indicator continues to indicate the CLOSED condition of the circuit interrupter between the time that such contacts are moving from the position separated by one-quarter of an inch and the position separated by one inch, the indicator would actually be indicating an erroneous condition of the circuit interrupter since the circuit interrupter is actually in an OPEN condition, albeit an intermediate one. Some circuit interrupters have employed an indicator which gradually changes from indicating a CLOSED condition to indicating an OPEN condition, such that it provides an indication that partially indicates “OPEN” and partially indicates “CLOSED”, which is likewise erroneous since, strictly speaking, the circuit interrupter cannot be in both conditions at once. It thus would be desirable to provide an improved circuit interrupter and indicator that meet these and other limitations known in the relevant art.